Snapchat tried to retrieve your product image but the request failed - 404, timeout, blocked content type, or invalid file. Products without a valid image are removed from catalogs.
Most often: CDN rate-limited Snapchat's crawler, image URL points to a hotlink-protected resource, file is technically valid but the wrong format (Snapchat accepts JPG, PNG, WebP), or images are gated behind authentication. Snapchat retries a few times then marks the product as ineligible.